Photographic apparatus



June 28, 1932.

T. w. CASE 1,865,055

PHOTOGRAPHIC APPARATUS Filed Dec. 4, 1928 l'aflro i? Patented June 28,1932 UNITED S'FATES PATENT OFFICE THEODORE WILLARD CASE, OF AUBURN, NEWYORK, ASSIGNOR TO CASE RESEARCH LABORATORY INC., OF AUBURN, NEW YORK, ACORPORATION OF NEW YORK rno'roenarnrc APPARATUS Application filedDecember 14, 1928. Serial No. 326,108.

This invention relates to certain new and improved apparatus forproducing or reproducing a photographic recordof light wave variationscorresponding to sound wave variations. V

It is found that when such a photographic record is produced or taken,oris reproduced while a film is moving over a support or runner that itis quite essential if an accurate record is to be produced, or ifreproduction is to be accurate, that the film shall move smoothly anduniformly in tight contact with the runner or track. Various forms ofapparatus have been designed in an attempt to accomplish the desiredfilm movement, such as the use of a spring-pressed shoe for main tainingthe film in tight contact with the track, and in such constructions ithas been customary and quite necessary that comparatively large shoesshould be used which eX- tend across the film and in operation act topress the film against the track, but the resultant friction injures thefilm and is apt to removeportions of the film, which in a short timedecreases the effectiveness ofthe pictures.

And the main object of this invention is the production of an apparatusfor the production or reproduction of sound pictures which may be usedwithout pressure shoes, or with various forms of comparatively smallpressure shoes, but in which the film is always maintained in tightcontact with the track due to the formation of the track and thepositioning of the means by which the film is drawn over the runner 'ortrack.

In my co-pending application Serial No. 733,560 I have disclosed amoving and sound picture camera in which the sound picture is takenwhile the film is moving around and with a rotating sprocket, and thefact that the film is curved longitudinally tends to pre vent lateralflexing or bending while the picture is taken, and the broad claims tothat apparatus are contained in said application.

This application among other features, differs in the stationaryposition of the supporting shoe and the fact thatlight may be projectedthrough the runner for taking or reproducingthe record, and thefurtherfact that the film is driven independently of the runner.

Other objects and advantagesrelate to the details of the structure andthe form and relation of the parts thereof, all as will more fullyappear from the following description taken in connection with theaccompanying drawing in which V Figure 1 is an elevation of an apparatusof this invention taken on line 1-1, Figure 2.

Figure 2 is a section taken on line 2-2, Figure 1.

Figure 3 is a section taken on line 33, Figure 1.

Figure 4 is an elevation illustrating a modified form of shoe.

Figure 5 is a section taken on line 55, Figure 4:.

Figure 6 illustrates a further modified form of shoe taken on line 66,Figure 7.

Figure 7 is a section taken on line 77, Figure 6.

It is customary to draw the film over a flat runner having a pair ofspaced tracks.

at opposite edges of the film. These tracks maintain the film flat in alengthwise direction, but in view of the fact that the film is notsupported at its intermediate portion, it is liable to buckle laterally,and the essential feature of this invention resides in the fact that thestationary runner 1 embodies a pair of spaced curved tracks over whichthe film M is drawn. A section of these surfaces of the runnerconstituting the tracks for supporting the opposite edges of a film isin the form of a segment of a circle, as illustrated in Fig. 2, and thisrunner may be supported in the camera in any suitable manner, as bybracket 2 secured by screws -3 to any portion of the camera or projectorwall B. The film is curved longitudinally as it moves across the lightaperture 4 and it is found that when a film is curved longitudinally,the tendency to bend or buckle laterally is removed.

This track or runner 1 has an openin 4 passing substantially radiallythrough it to permit exposure of a film moving over the track to lightrays passing through the opening. These light rays may kil be focussedin the form of a line of light upon the film, or a slit of desired formmay be provided in the runner -1.

The roll 5 over which the film moves toward the track l is positioned asshown, with its effective surface slightly at the rear of the track -1and the film is drawn downwardly along the roll 5 and over the track 1,as by sprocket 8- likewise positioned at the rear of the track 1- withits effective surface so positioned as to form a tensioning means whichholds the film tightly against the curved surface of the runner l as thefilm moves over the runner.

It will be apparent that the tension exerted by sprocket 6 is underordinary circumstances suflicient in itself to draw the film tightlyagainst the surface of the runner l as it moves over the opening 4.However, additional means may be provided, if desired, and in thedifferent figures various forms of shoes are illustrated, altho anymeans additional to the shape of the runner 1- and the position of thesprocket 6 may be provided for, additionally insuring proper contact offilm A with the curved surface of the runner 1.

In Fig. 1 there is shown a comparatively narrow shoe 7 which extendssubstantially the entire width of the film and has an opening 8- inalignment with the opening 4 through the runner 1.

This shoe may be spring-tensioned against the film in any suitablemanner, as for instance by mounting the shoes upon studs 9 which extendthrough a portion of the front wall of a tubular member 10telescopically mounted upon a second tubular member 11--- secured to thecameraframe, spring 12 being enclosed within the co-operating tubularmembers to normally tension the member 10 toward the shoe 7. V.

The tube 10 may be formed with a slot 18 in which a limiting pin l4l--is positioned, such pin being secured to the tube 11. In addition,springs 15- are interposed between the front wall of tube 10 and theshoe 7. The shoes are recessed to conform with the recess in the runnerand are adapted to contact with the film only at the points where thefilm overlies the tracks.

In Figs. 4 and 5 a slightly different form of construction is shown inthat two comparatively narrow shoes 16 are positioned at opposite edgesof the film and extend throughout substantially the entire length of thecurved track 1 and conform in curvature to the track. Means for mountingthe shoes 16 may be substantially the same as that shown in Figs. 1, 2and 3. V

In Figs. 6 and 7 a further modified form of shoe is shown in that theshoe 17 extends substantially the entire width of the film, but ispositioned above the opening 4. This shoe acts to maintain the filmagainst the upper portion of the curved surface of the track 1 andexerts sufficient pressure upon the film so that the tension produced byrotation of sprocket 6 in drawing the film over the runner 1 willmaintain the film tightly in contact with the track 1, particularly atthe aperture 4 through which the picture is taken.

As before stated, the essential feature of the curved surface of thetrack or runner 1- in combination with the tensioning or drawing meansfor the film, as for instance the sprocket 6, is so positioned that thedirectionof travel of the film is such as to maintain the film tightlyin contact with the curved surface of the runner 1. Preferably thesprocket -6 should be positioned so that its effective surface ispositioned slightly at the rear of a continuation of the curved surfaceof the runner so that the film is atall times tensioned against thecurved surface of the runner as it is drawn around the same, with rollmaintaining the film in' engagement with the teeth of sprocket 6.

Additional means, such as the. shoes illustrated, may be provided, ifdesired, as additional safeguards, and altho I have shown and describedspecific constructions as constituting embodiments of the invention, Ido not desire to restrict myself to the details of the same as variouschanges and modifications may be made within the scope of the appendedclaims.

I claim:

1. In an apparatus of the class described, a film-supporting memberhaving a pair of spaced continuously curved convex'runners, one of whichis provided with an aperture for the passage of light rays, a guideroller and pull sprocket, the film bearing surfaces of whichsubstantially form a continuation of the curved-runner surfaces, and'afilm-tensioning member disposed to the rear of said runners adapted tomaintain a film against the supporting surfaces as the sound trackportion of said film moves across said aperture.

2. In an apparatus of the class described, a film-supporting memberhaving a pair of spaced continuously curved convex runners, one of whichis provided with an aperture for the passage of light rays, thefilm'guiding surfaces of said runners being substantially greater inlength than the greatest cross-sectional dimension of'said aperture, aguide roller and pull sprocket, the film bearing surfaces of whichsubstantially form acontinuation of the curved runner surfaces, and afilm tensioning member of comparatively small contact pressure areadisposed to the rear of THEODORE WILLARD CASE.

